Sign frame key



FIG. 1 is a perspective view of a sign frame key showing our new design;

FIG. 2 is a front elevational view thereof, the rear elevational view being a mirror image thereof;

FIG. 3 is a left side elevational view thereof, the right side elevational view being a mirror image thereof;

FIG. 4 is top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The shading lines shown in the drawings represent the approximate three-dimensional contour of the design, and are not intended to indicate surface decoration. 

CLAIM The ornamental design for a sign frame key, as shown and described. 